This invention relates to downloading of media files through a communications network.
Music and other types of audio recordings are conventionally sold to consumers through stores or mail-order companies. When music or audio recordings are sold through these types of outlets, the recordings are usually distributed on tangible media, such as compact discs, magnetic cassette tapes, digital tapes, and so on. Another, alternative way of distributing music is to receive orders and distribute music electronically over a communications network, such as the Internet. A person can connect to a music provider and download music over the Internet, either for free or for a fee. A few examples of providers that make digital audio files available of downloading are RealNetworks Inc., Audible Inc., MP3.com Inc. and Emusic.com Inc.
The downloaded music can be played back with appropriate audio playback software on the user's computer, either while the computer is connected to the Internet (that is, through streaming playback of the audio data), or at later time. Examples of common software for playback audio files include the RealPlayer and the Windows MediaPlayer software. The user can organize his or her downloaded audio files into a personal jukebox on his or her computer. The user can also optionally transfer the downloaded audio files from his or her computer to a portable player that can play back audio files, so that he or she can leave his or her computer and still be able to listen to the previously downloaded audio files.
In many cases, the audio files are not stored at the server that hosts the shopping site from which the user buys the audio files. The site from which the user buys the audio files then typically issues a ticket and delivers the ticket to the user. The ticket serves as a proof of purchase and can be redeemed by the user at a different server, where the content is stored. When the user provides the ticket to the content server, the content server verifies the ticket to make sure that the ticket is genuine and delivers the corresponding content to the user's computer or playback device. This process can either be manual, that is, initiated by the user, or automatic. One example of a system that works according to this principle is the “proof of purchase” concept, provided by Intertrust Inc.
An alternative method is used in the EMMS system provided by International Business Machines Inc. (IBM). In this system, when a user buys audio content, he or she obtains a token. A corresponding, second token is also issued and sent to the content store. When the user wishes to redeem his token at the content store, the content store matches the user's token with the second token that was already sent to the content store by the electronic store where the user bought the audio files. If the two tokens match, the audio files are delivered to the user.
A problem with the EMMS and the “proof of purchase” concepts is that there is no way for the content store to verify that the user who redeems the ticket is the rightful owner of the ticket. If a ticket is intercepted on the way from the vendor to the user, the person who intercepts the ticket can redeem the ticket and obtain the content, and the content provider has no way of knowing that the content is not delivered to the rightful owner of the ticket.